Lifting-jack



(No Model.)

J. O. JOYCE.

LIPTING JACK.

No. 256,002. v Patented Aprg l, 1882.

m i I V gin"?! All" N. PETERS. PhuEO-Liihognphar, Wzshinglnn. DC.

UNrrno ra'ras ATENT JACOB O. JOYCE, OF DAYTON, OHIO.

Ll FTING JACK.

SPECIFICATION forming part of Letters Patent No. 256,002, dated April 4, 1882.

Application filed February 13, i882.

To all whom it may concern:

Be it known that I, JACOB O. JOYCE, a citizen of the United States, and a resident of Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification. I

My invention relates to improvements in lifting-jacks, and especially to the class called screw-j acks.

The invention consists in a lifting-jack combining in its structure a tubular base having an interior screw-thread, a hollow platen internally threaded in a direction opposite to the threads in the tubular base, an arm attached to the hollow platen and projecting downward therefrom and provided with aprojecting footpiece, aright-and-left-hand screw. arranged in the tubular base and hollow platen, and a head secured to said right-and-left-hand screw, and constructed ton'eceive a device by which to rotate the same for the purpose of raising the tubular platen and lifting the said downward] y-projectin g arm which is connected thereto, all of which will be more fully hereinafter described.

The invention embraces other features, all of which are clearly illustrated in the accompanying drawings, in which- Figure l is a perspective view, showing my improvement in position for operation. Fig. 2 is a central vertical section of Fig. 1. Fig. 3 is a perspective view of the screw'head, and Fig. 4 a perspective view of the wrench.

A represents the base of the jack. It is made hollow, and a right-hand screw-thread is cut in the bore thereof.

a represents a projection of the base to form a seat for the foot of ground-lift.

0 represents a hollow screw platen, the threads being left-hand, or in the'reverse direction to those of base A.

D D represent a right and-left-hand screwrod on gaging with those of baseA and platen G.

d represents the screw-head, which is rigidly attached to and around the screw-rod at the central pointof the right and left hand threads.

B represents a downwardly-projecting arm journaled or seated upon the platen C. It is preferably seated upon a flange, 0, cast integral with the platen C. It may, however, be attached to the platen G in various ways.

(No model.)

11 represents the foot rigidly attached to the arm B, and forming a seat for a lower or ground lift.

1) represents a channeled or grooved lugcast on the rear side of the arm 13.

a represents a rib or feather cast integral with the base A. The channels or lugs I) and the feather a form guides to hold the arm B in a perpendicular plane.

Various other modes of forming the guides may be used in lieu of those here shown.

01 represents the screw head attached to the screw D. It is provided with the annular groove 6 and sockets fupon either side of the annulus, to receive lugs on the wrench forturning the right-and-left-hand screw.

F represents a clutch-wrench. It is provided with elongated circularjaws H, which engage around thehead d and rest within the annular groove 6. off the head, the points of the forks are drawn together, so that their distance apart will be less than the diameter of the head within the groove.

I represents lugs cast upon the wrench F at the base of the forks, and of a shape and size adapted to fit the recess f either side of the annular groove 6, so that when the lugs l are projected into the recessesftheir engagement To prevent the wrench from coming will turn the head and raise the platen by.

the combined operation of the right-and-lefthanded screw. The elongation of thejaws H allows the lugs I to be withdrawn from the recesses e and the wrench turned loosely on the head for a new hold on the head.

The sliding clutch-wrench and corresponding-shaped head d may be variously modified and still retain the mode of operation herein described.

said platen and projecting downward therefrom, and having a foot-piece, I), a right-andleft-hand screw, 1) 1), arranged in the threaded tubular base and hollow platen, and a screwhead, (I, secured to the said right-and-left-hand screw, substantially as described.

2. A lifting-jack combining in its structure a tubular base, A, having an interior screwthread, a hollow platen, U, internally threaded in a direction opposite to the threads in the tubular base, an arm, B, connected with the said platen and projecting downward therefronnandhuving a loot-piece, b, a right-and-let'thand screw, D 1), arranged in the threaded tubular base and hollow platen, and a screwhead, d, secured to the said right-and-left-h and screw, and constructed with the annular groove 6 and sockets f, for receiving the arms H and lug I of a wrench, F, substantially as described.

3. In combination with the rightand-lefthand screw-jack, the downwardly-projecting arm B and foot 11, suspended upon the screwplaten C, and having the guides at and 1) formed upon the base A and arm B, substantially as herein set forth.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

JACOB O. JOYCE.

Witnesses:

IVARREN M NGER, GRAFTON G. KENNEDY. 

